He has seen the beach-dwelling birds defend their eggs in heavy storms until the moment the waves swallow their nests. But fireworks, for some reason, always seem to scare them off, he said.

"It's one of the biggest problems. The loud bangs and pops freak them out to the point that they don't come back," said Christman, 24, a Largo resident and recent St. Petersburg College graduate.

When the adults leave the nests, the young birds are left unprotected from predators or scurry into crowds.

Christman volunteers at Indian Shores, home to more than 600 of the 1,000 black skimmers in Pinellas County and 4,000 in Florida. Crows, pollution and erosion all threaten their natural habitat. Last month, Christman saw Tropical Storm Andrea wash away more than half their colony.

"The public isn't the enemy," he said. "We understand that we need their help for these birds to bring in the next generation."

Still, the week of Fourth of July, when beaches are likely to be more crowded, is a crucial time to protect the black skimmers, according to Saskia James, a volunteer coordinator at the St. Petersburg Audubon Society.

The black skimmer nesting areas at Indian Shores and Clearwater's Sand Key are roped off and protected by warning signs alerting beachgoers to keep away from the nests.

More than half of the Audubon Society's 70 volunteers will be dispatched at Indian Shores on Thursday, James said. Volunteers will watch the nests there and at Sand Key all day.

"Black skimmers are like the sports cars of the air, and we want to do whatever we can to protect them," James said. "They're part of what makes this area so special."

Matt McKinney can be reached at mmckinney@tampabay.com or at (727) 445-4156.